Apparatus for removing the casting in continuous casting processes



g- 11, 1959 P. s. E. FREDRIKSSON ETAL 2,893,650

APPARATUS FOR REMOVING THE CASTING IN CONTINUOUS CASTING PROCESSES FiledJune 24, 1955. 4 Sheets-Sheet 1 Aug. 11, 1959 s. E. FREDRIKSSON ET2,53%5650 APP FOR REMOVING THE STI IN co NUOUS CASTING PRO SES FiledJune 24, 1955 4 Sheets-Sheet 2 264 2 4 i JZQ 50 3362) 5/52 66697 0 7/7Z3 w L Aug. 11, 1959 P. s. FRE lKssoN, ET 2,898,650

APPARATU OR RE VING THE CAST IN CONTINUOUS CASTING PROCESSES Filed June24, 1955 4 Sheets-Sheet 3 Aug. 11, 1959 Filed June 24, 1955 P. S. E.FREDRIKSSON ET AL APPARATUS FOR REMOVING THE CASTING IN CONTINUOUSCASTING PROCESSES 4 Sheets-Sheet 4 2,898,65fi Patented Aug. 11, 1959fire APPARATUS FOR REMOVING THE CASTING 1N CONTINUOUS CASTING PROCESSESPer S. E. Fredrilrsson, Anders l. Arnelo, Karl B. L'ofgren,

and Lars G. W. Lotvik, Vasteras, Sweden, assignors to AktieholagetSvenska Metallverken, Vasteras, Sweden,

a Swedish company Application June 24, 1955, Serial No. 517,878

Claims priority, application Sweden June 24, 1954 5 Claims. (Cl. 22-572)The present invention relates to a method and means for the extrusioncasting of ingots of ferrous metals and non-ferrous metals according towhich the ingots are discharged from the casting machine in asubstantially vertical direction.

Up to now such extrusion casting has been carried out :substantially ina discontinuous or intermittent manner. .In doing so it has beencustomary to utilize a plug which forms the bottom of the mold of thecasting machine and as the material solidifies in the mold the columnformed is moved downwardly. Upon completion of downward movement of theplug it rests on a table which .is lowered as the ingot is dischargedout of the mold. When the ingot has been completed it is removed fromlthe table, whereupon the table is elevated and a plug inserted in thebottom of the mold for commencing the casting of a new ingot. Theinterruption in casting thus =caused between the production of each newingot means -.that the full capacity of the casting machine cannot besatisfactorily utilized. For better utilization of such capacity it hasbeen suggested to adopt a continuous ;casting procedure in which aninterruption of casting be- .tween the different ingots is avoided, sothat a continuous column is taken out of the casting machine, whichcolumn during its vertical movement downwardly is cut off for obtainingan ingot of a desired length. Accord- .ing to one suggestion thesolidified column is fed downwardly between positively opera-ted feedingrolls, the feeding speed of which defines the rapidity of the downwardmotion of the column. The column then is cut by .means of a specialcutting machine which accompanies 1 the column in its downward motion sothat the motion of the cutting means will be synchronized with thefeeding operation of the feeding rolls. In such procedure, however, verycomplex guide and control means are required :and the risk of errors inoperation is considerable. A further deficiency connected with suchsuggested arrangement resides therein that it cannot operate in asatisfactory way immersed in water which is desirable for cooling of theingots.

The present invention deals with a method and a means 'by which it willbe possible to obtain a very high degree of utilization of the capacityof the casting machine, which capacity will approach that of continuouscasting and at the same time the objectionable features encountered inthe continuous casting described above are avoided and simplicity andsecurity in operation of the intermittent casting procedure ismaintained.

In applying the method embodying this invention, ingots of a limitedlength are formed in an essentially continuous operation. Such aprinciple was earlier suggested, wherein the difierent ingots wereseparated in relation to each other by the utilization of partitionmembers of suitable material. However, it has been proved that suchsuggested partition or separating members which were of a solid naturecannot advantageously be used in practice. Thus, the perimeter surfaceof the separating or partition members has to be made of such value,that metal is not allowed to pass between the partition member and thesurrounding inner surface of the mold. In such case, however, apartition member closely fitting the wall of the mold, will by reason ofthe heating brought about When supplying molten metal above the member,expand and jam in the mold. In accordance with this invention a veryeffective separation of the ingots is obtained while simultaneouslypreventing molten metal from flowing around the sides of the separatingmaterial by using metal chips or the like eg. of the same metal as thatwhich forms the ingots. In using such chips they are packed in the moldon top of the solidified ingot, thereby effectively preventing the flowof molten metal into the space between the ingot and the wall of themold. Regarding the height of the plug of chips it may be mentioned thatthe same frequently does not amount to a figure exceeding 10 mm.Furthermore the resilient consistency of the cake of seal ing chipspermits thermal expansion to occur without the cake getting jammedbetween the walls of the mold. By using the same metal as that of theingots no injurious effect upon the composition of the ingots resultsand in the subsequent handling the presence of impurities is avoided. Itis preferred to have a plug of a material having as high a heatconductivity as possible. Therefore, this method is particularlyadvantageous in the production of metal or metal alloys includingcopper. In order to be able to fully utilize the possibility of castingseparated ingots in immediate succession according to the invention itis desirable to have the finished ingot immediately removed from theplace below the casting machine 'to which the ingot has been moved bythe feed rolls in order to provide space for the next ingot and thepresent invention also includes an arrangement for such rapid removal ofthe ingots.

Figure 1 shows a diagrammatic vertical section through a pit forreceiving ingots'arranged below 'the casting machine, which pit isprovided with an arrangement embodying the invention.

Figure 2 diagrammatically shows certain control means included in thearrangement shown in Figure -1.

Figure 3 diagrammatically shows certain other control'me'ans included inthe arrangement shown in Figure 1. i i

Figure 4 diagrammatically shows a modified embodimerit of the controlmeans shown in Figure 2.

Figure 5 is a chart of the characteristics of a driving means for aningot receiver platform shown in Figure 4.

Figure 6 diagrammatically shows a further modified embodiment of thecontrol means shown in Figure 2.

In Figures 1 to 3 inclusive, reference numeral 1 diagrammaticallyindicates a melting pot, heat-keeping furnace, ladle or the like towhich metal may be supplied in a way not shown. Reference numeral 2designates a valve means for the control of the flow of molten metalthrough the pipe 3. Reference numeral 4 diagrammatically indicates amold designed as a cooling ring in which the metal will solidify whileflowing downwardly. The solidified ingot 5 is fed downwardly by means'oftwo sets of feeding rolls a, '7, which in the embodiment shown arepositively operated. Arranged in a pit 8 located below the rolls s, 7 isan ingot receiver lll' pivotally supported in a bearing 9, whichreceiver in the embodiment shown is formed as a framework. The framework"maybe tilted from the vertical position A shown in full lines in Figurel in a counter clockwise direction to the position B indicated by dottedlines. The movement is limited by the stops ill and 12. Arranged in theframework 10 is an ingot receiving platform 13, which is adapted to bemoved longitudinally of the framework. Furthermore the ingot receiver isprovided with supporting rollers 14 so as to form a roller path in thelongitudinal direction of the ingot receiver. Pivotally supported on oneside of the pit is a roller path portion 15, which in its receivingposition shown in the figure forms an extension of the ingot receiver 10when the ingot receiver 10 occupies its position B. The roller pathportion 15 is pivotally supported at its upper end in a bearing 16, withits lower end abutting against a stop 17. A hook member 18 is pivotallysupported by the lower end of the roller path portion 15'. The hookmember 18 may be lifted by means of a wire 19 while passing throughslots or openings in the upper portion of the ingot receiver 10. Therebythe roller path portion 15 by means of the wire 19 and the hook member13 fixed therein may be lifted up to approximately a horizontalposition.

The turning of the ingot receiver between the positions A and B may becontrolled by means of the wire 20, which is passed over pulleys 21, 22to the winding drum 2?: which is operated by the motor 24 via thegearing 25.

The displacement of the ingot receiver platform 13 along the ingotreceiver 19 is controlled by the wires 26, 27 1 which are arranged inpairs in a side by side relation and passed over pulleys 28, 30, 32, 34and 29, 31, 33, 35, respectively, from the winding drums 36 and 37,respectively, which are driven by the motor 39 via the gearing 38. i Thepulleys 34, are adapted to actuate pistons in a way which will beevident from the diagrammatic showing in Figure 2. As will be evidentfrom this figure the pulley 34 is mounted at one corner of an angularpiece 40 which is pivotally supported at another corner on a bracket 41.Pivotally connected to the angular piece 40 is a piston rod 42, thepiston 43 of which operates in the cylinder 44. Also shown in Figure 2is an angular piece 45 which is pivotally connected to the bracket 46.Journalled on the angular piece 45 is the pulley 35 for the wire 27 andpivotally connected to the piece 45 is the piston rod 47, the piston 48of which operates in the cylinder 49. Although the angular pieces 40 and45 and accessories, for the sake of clearness, are shown in Figure 2 aslocated alongside, in reality they are preferably located one behind theother as shown in Figure 1. The portion of the cylinder 44 located belowthe piston 43 communicates through a conduit 50 with the interior of thecylinder 51 inwhich operates a piston 52. Fixed to the piston 52 is apiston rod 53 to the other end of which is fixed a second piston 54which operates in a cylinder 55. The cylinder 55 communicates throughthe conduit 56 and a reduction valve 57 with a conduit 58 whichcommunicates with an air supply, not shown.

The portion of the cylinder 49 located below the piston 43 communicatesthrough the conduit 59 with the portion of the cylinder 44 located abovethe piston 43. The system comprising the lower portion of the cylinders44, 49, conduits 5t 59 and the left portion in Figure 2 of thecylinder51 is arranged to be filled with a suitable fluid mediumsuch asoil.

A switch 60 is arranged to be actuated by an arm 61 which is connectedto the angular piece 40. This switch 60 closes and opens the electricalcurrent supply to the motor 39.

In a similar manner as shown in Figure 3, the pulley 2.2 for the wire 20is mounted on an angular piece 62 pivoted to a bracket 63 and connectedto a piston rod 64,

cates through a. conduit 73 via a reduction valve 74 with a conduit 75which communicates with an air supply. Arranged on the angular piece 62is an arm 76 which actuates a switch 77 controlling the motor 24.

For the control of the turning movement of the hook member 18 inrelation to the roller path portion 15 and also the turning of thelatter about the bearing 16, the wire 19 is passed over a winding drum78 which via the gearing '79 is driven by the motor 80. Passed over theshaft of the winding drum 78 is an endless chain 81 which also is passedover a sprocket wheel 82 which is arranged on the same shaft as a camplate 83. This cam plate actuates two switches 84 and 85 which controlthe motors 2.4, 39 and 30 in a way that will be later described.

The manner of operation of the arrangement is as follows:

In course of casting the ladle or metal receiver 1 is filled with moltenmetal. When the valve 2 is lifted the molten metal will flow through thepipe 3 downwardly into the mold 4, in which it is cooled in a suitableway, e.g. by means of water cooling. However, prior to opening the valve2 the mold is closed adjacent the bottom by a so called blind-castinginserted therein. In subsequent casting operations the upper end of thepreceding ingot will serve as a bottom in the mold, metal chips beingpacked down in the mold and distributed so as to form a parting plug orcushion above the ingot. When a preceding ingot is fed downwardly by thefeeding rolls 6, 7 the new ingot in course of casting is fed downwardlyresting upon the top end of the preceding ingot but separated thterefromby a parting member of metal chips in a way described. The chips areshoveled or otherwise deposited in the mold 4 to the desired thicknessand serve to separate one ingot from the next. The speed of movement ofthe ingot is selected in such a manner that the solidification willcontinue in a desired way.

Before the upper end of the previous ingot has passed the lower set ofrolls 6, 7, the ingot receiver platform 13 has been moved into theposition shown in the drawing. While descending, the lower end of theingot will strike against the ingot receiver platform 13 causing anincreased load on the wires 26, 27, so that they are tightened. Thewires through the pulleys 34, 35 and the angular pieces 40 and 45 willurge the piston rods 42, 47 and pistons 43 and 48, respectively,downwardly in the cylinders 44 and 49, respectively. This will force oilfrom the cylinder 44 through the conduit 50 into the cylinder 51, sothat the piston 52 and with it the piston rod 53 and the piston 54 areurged to the right in Figure 2. against the air pressure in the rightportion of the cylinder 55. The reduction valve 57 is set in such a waythat the pressure exerted by the air against the piston 54 and therebyagainst the piston 43, which is connected to the angular piece 40,balances the weight of the ingot receiver platform 13. Thus, when theingot imposes a load on the ingot receiver platform, the pressure set onthe reduction valve 57 will be exceeded, whereupon the piston 54 willmove to the right and the piston 43 downwardly in the cylinder 44.Thereupon the actuating arm 61 actuates the switch 60, so that thecircuit to-the motor 39 is closed, whereupon the ingot receiver platform13 starts to move downwardly. The angular piece 45 carrying the pulley35 and the piston means 48 will similarly control the operation ofswitch 60. The reason for having two wires 26, 27 is the fact that it isdesired to avoid transverse forces upon the ingot receiver from theingot receiver platform, which among other things would be encounteredif the platform were merely supported by one wire. Thus, when the ingotreceiver plat form 13 moves downwardly, the load on the platform willdecrease, whereupon tension in the wires 26, 27 will also be decreased.Due to this the arm-61 shown in Figure 2 will actuate the switch 60 toopen the circuit to the motor 39. The downward movement of the ingotreceiver platform is then interrupted whereupon the load exerted by theingot against the platform is again increased and the describedprocedure repeated during downward movement of the ingot.

The downward movement of the platform 13 is related to the rotation ofrolls 6 and '7 to support the ingot and prevent elongation, but withoutexerting compressive forces thereon during downward movement sufiicientto distort the same. Since the ingot upon leaving the rolls 6 and 7 isstill in a deformable or semi-plastic condition, it is necessary tosupport the same by means of the platform 13 during downward movement,in order to prevent stretching or other distortion of the ingot.

When the ingot receiver platform 13 has moved downwardly to such anextent that the upper end of the ingot has left the lower set of rolls7, the entire weight of the ingot will rest upon the platform 13. Thenthe wires are again tightened so that the switch 60 is closed and themotor 39 will continue operating until the ingot receiver platform 13has arrived at its bottom position in the ingot receiver 10. Upon itsarrival at this position a limit switch, not shown, is actuated whichswitch will cause the motor 39 to stop and also operates to start themotor 24 and pay out the wire 20, whereupon the ingot receiver and alsothe ingot receiver platform moves counter clockwise as viewed in Figure1 into the position B shown in dotted lines, wherein the motion of theingot receiver is arrested by the stop 12. This swinging movement of theingot receiver is facilitated by the layer of chips forming a partingmember between successive ingots thereby permitting moving of one ingotaway from the next. The current supply to the motor 24 is now opened bymeans of another switch, not shown, and the motor 39 is started in areverse direction, so that the ingot receiver platform is moved upwardlyraising the ingot and discharging the same upon the roller path 15. Whenthe ingot receiver platform 13 has arrived at its topmost position inthe ingot receiver 10, the current supply to the motor 39 is opened andthe motor 80 is started, whereupon the hook 18 by means of the wire 19is moved in below and behind the lower end of the ingot which has movedout of the ingot receiver onto the roller path 15 thereby lifting theroller path 15 and the ingot lying thereon up to a horizontal position.This engagement of the hook 18 with the lower end of the ingot ispossible by reason of the fact that as the ingot leaves the ingotreceiver the ingot moves transversely onto the roller path therebyexposing a portion of the lower end of the ingot. The motor 86 isstopped by a limit switch 84 cooperating with the cam plate 83. Atposition D of the rollers 15 the motor 39 is again started in a reversedirection, whereupon the ingot receiver platform 13 is moved a distancedownwardly in the ingot receiver 19 corresponding to the verticalposition indicated in full lines in Figure 1. In this position of theingot receiver platform a limit switch is actuated which starts themotor 24. Then the ingot receiver 10 is moved about the bearing 9 andraised up into its vertical position. The ingot receiver platform 13 andingot receiver 10 now again are in position for receiving the next ingotwhich simultaneously has been carried downwardly by the feed rolls 6, 7,whereupon the procedure is repeated. Thereafter the ingot is removed ina suitable way from the roller path 15 and the path is then swung backinto the position shown in full lines in Figure l.

Concerning the automatic control of the movement of the ingot receiver143 about the bearing 9, this substantially coincides with the controlof the movements of the ingot receiver platform 13 and is performedsubstantially as follows:

Thus, when the ingot receiver platform 13 in its strict verticalmovement from the position shown in Figure 1 reaches its bottom positionin the ingot receiver, the platform will actuate a switch, not shown,which is arranged to close the current supply to the motor 24. Themovement of the ingot receiver 10 then is started and this movement iscontinuous until the receiver engages the stop 12, viz. to the positionB in Figure 1. At the same time the ingot receiver also actuates aswitch, not shown, which will open the current supply to the motor 24and start the motor 39 in a reverse direction of rotation. The ingotreceiver platform 13 is thereby moved in a slanting position upwardlyalong the ingot receiver 10 and carries with it the tilted ingot rollingon the rollers 14 and the roller path 15. In a certain position inconnection with the stop 12 the ingot receiver platform 13 actuates afurther switch, not shown, which controls the motor 80. Motor via thegearing 79 and the wire 19 lifts the hook member 18 upwardly to aposition behind the lower end of the ingot. Continued movement of thewire 19 raises both the hook member 18 and the roller path 15 with theingot resting thereon upwardly approximately to the position D inFigure 1. Due to the rotation of the motor 80 the cam plate 83, however,via the chain 81 has been caused to rotate, whereupon at a pointcorresponding to the position D the plate will actuate one of thecontacts 84 or 85 which closes the current supply to the motor 39, sothat the same starts the upward movement of the ingot receiver platform.When subsequent thereto the ingot receiver platform has reached thedesired position in the receiver 10 a limit switch, not shown, will beactuated, so that the motor 39 is stopped at the same time as: the motor24 is started thereby moving the ingot receiver back into its verticalposition shown in Figure 1.

During all movements hitherto described which are transmitted to theingot receiver 10 from the motor 24 through the wire 2% a dcfinit econtrol of the tension in the wire 21) is maintained due to the factthat in connection with Figure 3 the angular piece 62 is prevented frombeing swung downwardly by the piston 65, which rests: upon an oil pad inthe cylinder 66, conduit 67 and the left end of the cylinder 68. Thisoil pad is counteracted in turn by the twin-piston 69, 70, 71 in thatthe piston '71 is exposed to air pressure in the cylinder 72. Thispressure is maintained through the communication of the cylinder 72 witha source of pressure 75 via a reduc'-- tion valve 74, which isadjustable in such a way that the: force transmitted by the wire 26during the turning movements of the ingot receiver is not suflicient toswing the angular piece 62 downwardly which would mean that the contactarm 76 would be removed from the switch 77 thereby stopping the motor24.

However, when the ingot receiver 10 has been returned from its slantingposition B into its vertical position A the motor 24 continues operatingto apply a force to the wire 20 exceeding that for which the controlsystem is adjusted according to Figure 3. Consequently the angular piece62 then is depressed so that the contact arm '76 will be removed fromthe switch 77, opening the current supply to the motor 24 which therebyis caused to stop. The force applied to the wire 20 remains there afteruntil the motor, after being reversed, is started again at which timethe ingot receiver platform 13 in the bottom position of its verticalmovement actuates the switch, not shown, arranged at this pointwhereupon the procedure is repeated.

In relation to the different movements of the ingot receiver platform 13it should be emphasized that it is necessary to automatically move theplatform to a proper position to receive the ingot coming from thecasting machine before the ingot has left the sets of rollers 6, 7. Ifthe downward movement of the ingot receiver platform 13 is too slow inrelation to the movement of the ingot this may affect the upper,relatively soft portion of the ingot, whereupon an unfavourabledeformation may be caused. Such deformation may subsequently causetrouble during discharge of the ingot from the ingot receiver.

However, if the downward movement of the ingot receiver platform 13 istoo rapid in relation to the downward feeding motion of the ingot, theingot when leaving the feedingr ollers, 6, 7 may...drop downwardlycausinga blow against the..platform.. ,In case, of great ingot weightssuch a blow may, do damage to the entire structure. Consequently in anideaLcase .it should be ensured that the platform willtouch with asmallpressure the end of theingot whenthe ingot is just leaving thefeedrolls and that the operation', of the plat form is entirely.automatic. .3

Such an ideal-conditionis obviously difficult to obtain but theinvention using the alternative described above for the automaticcontrol of the platform, offers the possibility of satisfying praeticalrequirements in this 7 respect.

In the-preceding description merely, the control of the limit switches-60,-77 and,84 has been described in detail. Howeven the .nernainingswitches which ,are locatedbelow-thewaterlevel in the pit 3 maybecontrolled. in a corresponding way whichshould be obivous to eachartisan as indicatedbythat which has been described concerning the lastmentioned switches.

In the .above; described alternative for they control of the movementand adjustment of the ingot receiver ceiver platform is disclosed ascomprising-a lower mem- I ber 86 on which is supported by means ofsprings 87 an upper member 88. Fixed to the member, is a wire 89 whichruns over the pulley 90 to the winding H drum 91. The wire 89corresponds to the Wires 26,27 in the embodimentshown in Figure 1 andFigure 2. The winding drum 91 is arranged on the same shaft as themotor92 corresponding to themotor 39 in Figure 1. Fixed to the member.86 is a control wire 93 which runs over pulleys 94, 95, 96 to thewinding drum 97. The windingdrum 97 in its rotation actuates the movablecontact of a potentiometer 98. ,Fixed to the upper member 88 of theingot receiver platform via a lever is a wire 99 which runs over pulleys100,.and 101 to a winding drum 102., The winding drum 102 actuates themovable contactin another. potentiometer 103. .The potentiometers 98 and103.are suitably of .multi-coiled P0161111".

ometer type and form together ,a completeWheatstone bridge. A furtherbridge is arranged which includes the potentiometers 104 and 105 ofwhich the potentiometer 104- preferably is of the multi-coiled. type. aIncluded in the bridge circuit are also resistances 10-6,

107, 108, 109 symmetrically arranged in relation to the potentiometers104, and 105. Coupled in parallel to the potentiometer 104-is a furtherpotentiometer 110.

The movable contacts of the potentiometers 103 and.

a gearing 115 operates a rheostat116. The rheostat -j controls the fieldcircuit of a DC. generator 117 which supplies voltage to the motor 92.The DC. generator is mechanically coupledto :an AC. motor 113, which.

is drivenby a suitable-source of current,..not shown.

The gearing 115 operates the-movable contact of thepotentiometer 104.The =movable contact of the potentiometers 98, --104 -are electricallyconnected to each other bymeans of the' lead 119. The-servo -amplifier111 is supplied with electrical current through the leads- 120 fromtheyline voltage. The above described bridges,

in 'which are included thepotentiometers98,;103and 104,105,"respectively,'are supplied with current from the same line voltagevia the transformer 121 through 3 the leads 122 and 123, respectively.

Themode of operation of the arrangement shown in Figure 4 is as follows:When an ingot from the feed rolls designated by 6 and 7 in Figure 1 isfed downward ly towards the ingot receiver platform ,86, 87, 88, the;

platform remains stationary in the same position as has been shown.concerning the platform 13 in Figure 1. When the bottom of the ingotabuts the upperplatform member 88, this member startsto move downwardlycompressing the springs 87. "In such positioning the wire;

99 over the winding drum 102 will displace the movable contact of thepotentiometer 103; This will cause an unbalance .in the correspondingbridge system which causes the motor 92 to be actuated by the servoamplifierj Thereby the lower platform member 86- via the wire 89 will bemoved downwardly. At the;

111 and start.

same time as the motor 92'is actuated, the movable potentiometer 104 ofthe other bridge system is actuated. via the gearing 115 in such a waythat it tends to restore the balance in the bridge system.

The position of the lower platform member 86. is

indicated in the bridge system through the:intermediary of the wire 93which over the winding drum 97 ,actu

ates the movable contact of the potentiometer 98. By

adjusting the potentiometer which may take place potentiometer thesensibility of the arrangement may be adjusted, viz. the extent ofmovement of the lower platform member 86 which is caused by a certainmovement of the upper platform member 88. By adjusting thepotentiometers 105 and 110 it is thus rendered pos- I s'ible to causethe upper part 88 of an ingot receiver platform to follow the ingot inits vertical movements with a desired abutting pressure.

In contrast to the condition in the embodiment of Figures 1 to 3inclusive the ingot receiver platform,

the rheostat operates within the range of the characteristics designatedby a. When the ingot has left the rollers and substantially entirelycompresses the springs 87 the operation is in the range I) which, aswill be evident,

results in an increased speed of the motor and additionally of themovements of the ingot receiver platform.

It should also be emphasized that the described arrangement has beenmerely set forth in a diagrammatic way and that in practice obviouslycounter-balances or springs must be arranged for the returning movementof the wireswhich is obvious to any artisan in this field.

Furthermore it should be emphasized that the arrangement described withreference to Figure 4 merely substitutes for those parts of thearrangement of Figure 1 which controls the movement of the ingotreceiver platform. The hook member 18 and roller path 15 may 7 beoperated for instance in the same way as has been stated in connectionwith Figure 1.

Shown in Figure 6 is another alternative for the control of the movementof the ingot receiver platform. Here substantially the same principle isapplied as is used in Figure 4, the potentiometers 98, 103, however,being replaced by a potentiometer 124 and a differential gear 125. Thus,in the drawing reference numeral 126 This is obtained egg. by providingthe driving platform member.

A wire 128 runstrom-the -upper--- platform member 126, and a wire 129from the lower platform member 127 which over winding drums controlopposite gears 130 and 131 in the differential 125. The remaining twogears 132 in the differential actuated by the gears 130 and 131 drivethe movable contact in the potentiometer 124. The potentiometer 124 isbridgecoupled with the potentiometer 133, which responds to thepotentiometer 104 according to the embodiment of Figure 4. Thepotentiometers 110 and 105 in the embodiment according to Figure 4respond to the emlbodiment according to Figure 5 of the potentiometers134 and 135, respectively. In other respects the arrangement accordingto Figure 5 is similar to the arrangement according to Figure 4 and themode of operation is the same. The bridge 103, 98 shown in Figure 4 isreplaced by the differential 125- and the potentiometer 124.

The invention is not limited to the embodiment shown and described butmay be varied in various respects within the scope of the basicinventive idea.

Having now described the invention, what we claim as new and desire tosecure by Letters Patent, is:

1. An arrangement in machines for the substantially continuousproduction of elongated metal ingots by continuous casting duringmovement substantially in a vertical direction through a bottomlessmold, said machine including pairs of positively operated feed rollslocated below the mold and arranged to feed the ingot in course ofcasting downwardly into an ingot receiver including a platform which ismovable downwlardly in response to the feeding movement of the ingot bysaid feed rolls and control means for causing said platform to movedownwardly in relation to the feeding of said ingot by said feed rollsto support said ingot with a substantially constant pressure and preventdistortion thereof during downward feeding movement, said platformhaving a range of movement sufiicient to support said ingot afterdischarge from said feeding rolls.

2. An arrangement as claimed in claim 1, characterized in that theplatform is movably suspended from wires in the ingot receiver, thewires being passed over pulleys or the like to a winding drum arrangedoutside the ingot receiver, a motor for driving said winding drum andmeans including at least one of the wires being arranged to actuate aswitch in response to the load on said one Wire, which switch operatesto close and open respectively the circuit to said motor.

3. An arrangement as claimed in claim 2, characterized in that the loadon said one wire is balanced by a pres- 10 sure medium system whichmaintains a continuous predetermined adjustable maximum counterforce onsaid one wire, in such a way that the switch is actuated to open themotor circuit when the tensile stress in the Wire is less than thebalancing load of said pressure system, said system including a pistonand cylinder with the piston supporting the load on said one wire andwith the cylin der connected to a predetermined source of fluidpressure.

4. An arrangement as claimed in claim 1, characterized in that theplatform includes a resiliently mounted supporting plate for engagingthe end of the ingot, the platform and supporting plate each beingcounterbalanced by means of a loaded wire control system, a drive motorfor moving said platform and a differential potentiometer systemoperable in response to differences in vertical movements between thesupporting plate and the platform to control said drive motor forcontrolling the vertical movements of said platform in response to thefeeding movement of the ingot.

5. An arrangement as claimed in claim 1, characterized in that theplatform includes a resiliently mounted supporting plate for engagingthe end of the ingot, the platform and supporting plate each beingcounter-balanced by means of a loaded wire control system, a drive motorfor moving said platform and a mechanical differential device includinga potentiometer system operable in response to differences in verticalmovements between the supporting plate and the platform to control saiddrive motor for controlling the vertical movements of said platform inresponse to the feeding movement of the ingot.

References Cited in the file of this: patent UNITED STATES PATENTS2,176,990 Crampton Oct. 24, 1939 2,301,027 Ennor Nov. 3, 1942 2,334,929Hone Nov. 23, 1943 2,560,639 Giesler et al. July 17, 1951 2,582,329Harter et al. Jan. 15, 1952 2,709,284 Evans et al May 31, 1955 2,743,700Toulmin May 1, 1956 2,753,605 Carleton July 10, 1956 2,806,263 HoganSept. 17, 1957 FOREIGN PATENTS 721,386 Great Britain Jan. 5, 1955725,323 Great Britain Mar. 2, 1955

